In recent years, non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries and nickel hydrogen batteries have been used as so-called portable power sources for personal computers, hand-held terminals, and the like, and as power supplies for vehicle propulsion. In particular, lightweight lithium ion secondary batteries able to achieve high energy densities can be advantageously used as high output power sources for propelling vehicles such as electric vehicles, hybrid vehicles and plug-in hybrid vehicles.
In such non-aqueous electrolyte secondary batteries, a power-generating component is typically constituted by arranging a sheet-shaped positive electrode and a sheet-shaped negative electrode, which are obtained by providing a positive electrode mixture layer and a negative electrode mixture layer on the surface of a positive electrode current collector and a negative electrode current collector (which may be current collector foils) respectively, so as to face each other in a mutually insulated state. Such power-generating components have a layered structure obtained by winding or layering. In addition, constitutions are known in which current collector parts are formed so that a positive electrode current collector or negative electrode current collector is exposed at both edges of this type of layered structure, and power is inputted and outputted from an electrode body by connecting current collector terminals to these current collector parts. Welding is typically used to connect such current collector terminals. In addition, related features are disclosed in, for example, Patent [Literature 1]